/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package ai.platon.pulsar.common.domain;

import ai.platon.pulsar.common.Strings;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import java.io.IOException;
import java.io.InputStream;

/**
 * For parsing xml files containing domain suffix definitions. Parsed xml files
 * should validate against <code>domain-suffixes.xsd</code>
 *
 * @author Enis Soztutar &lt;enis.soz.pulsar@gmail.com&gt;
 */
class DomainSuffixesReader {

    private static final Logger LOG = LoggerFactory.getLogger(DomainSuffixesReader.class);

    DomainSuffixes read(DomainSuffixes tldEntries, InputStream input) throws IOException {
        try {
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            factory.setIgnoringComments(true);
            DocumentBuilder builder = factory.newDocumentBuilder();
            Document document = builder.parse(new InputSource(input));

            Element root = document.getDocumentElement();

            if (root != null && root.getTagName().equals("domains")) {
                Element tlds = (Element) root.getElementsByTagName("tlds").item(0);
                Element suffixes = (Element) root.getElementsByTagName("suffixes").item(0);

                // read tlds
                readITLDs(tldEntries, (Element) tlds.getElementsByTagName("itlds").item(0));
                readGTLDs(tldEntries, (Element) tlds.getElementsByTagName("gtlds").item(0));
                readCCTLDs(tldEntries, (Element) tlds.getElementsByTagName("cctlds").item(0));

                readSuffixes(tldEntries, suffixes);
            } else {
                throw new IOException("xml file is not valid");
            }
        } catch (ParserConfigurationException | SAXException ex) {
            LOG.warn(ex.getMessage());
            throw new IOException(ex);
        }

        return tldEntries;
    }

    void readITLDs(DomainSuffixes tldEntries, Element el) {
        NodeList children = el.getElementsByTagName("tld");
        for (int i = 0; i < children.getLength(); i++) {
            tldEntries.addDomainSuffix(readGTLD((Element) children.item(i),
                    TopLevelDomain.Type.INFRASTRUCTURE));
        }
    }

    void readGTLDs(DomainSuffixes tldEntries, Element el) {
        NodeList children = el.getElementsByTagName("tld");
        for (int i = 0; i < children.getLength(); i++) {
            tldEntries.addDomainSuffix(readGTLD((Element) children.item(i), TopLevelDomain.Type.GENERIC));
        }
    }

    void readCCTLDs(DomainSuffixes tldEntries, Element el) throws IOException {
        NodeList children = el.getElementsByTagName("tld");
        for (int i = 0; i < children.getLength(); i++) {
            tldEntries.addDomainSuffix(readCCTLD((Element) children.item(i)));
        }
    }

    TopLevelDomain readGTLD(Element el, TopLevelDomain.Type type) {
        String domain = el.getAttribute("domain");
        DomainSuffix.Status status = readStatus(el);
        float boost = readBoost(el);
        return new TopLevelDomain(domain, type, status, boost);
    }

    TopLevelDomain readCCTLD(Element el) throws IOException {
        String domain = el.getAttribute("domain");
        DomainSuffix.Status status = readStatus(el);
        float boost = readBoost(el);
        String countryName = readCountryName(el);
        return new TopLevelDomain(domain, status, boost, countryName);
    }

    /** read optional field status */
    DomainSuffix.Status readStatus(Element el) {
        NodeList list = el.getElementsByTagName("status");
        if (list == null || list.getLength() == 0)
            return DomainSuffix.DEFAULT_STATUS;
        return DomainSuffix.Status.valueOf(list.item(0).getFirstChild().getNodeValue());
    }

    /** read optional field boost */
    float readBoost(Element el) {
        NodeList list = el.getElementsByTagName("boost");
        if (list == null || list.getLength() == 0)
            return DomainSuffix.DEFAULT_BOOST;
        return Float.parseFloat(list.item(0).getFirstChild().getNodeValue());
    }

    /**
     * read field countryname
     */
    String readCountryName(Element el) throws IOException {
        NodeList list = el.getElementsByTagName("country");
        if (list == null || list.getLength() == 0)
            throw new IOException("Country name should be given");
        return list.item(0).getNodeValue();
    }

    void readSuffixes(DomainSuffixes tldEntries, Element el) {
        NodeList children = el.getElementsByTagName("suffix");
        for (int i = 0; i < children.getLength(); i++) {
            tldEntries.addDomainSuffix(readSuffix((Element) children.item(i)));
        }
    }

    DomainSuffix readSuffix(Element el) {
        String domain = el.getAttribute("domain");
        DomainSuffix.Status status = readStatus(el);
        float boost = readBoost(el);
        return new DomainSuffix(domain, status, boost);
    }
}
